Fuel injection system



y 1938- -J. s. WALTERS 2,117,380

FUEL INJECTION SYSTEM Filed Jan. 30, 1955 ATTORNEY;

Patented May 17, 1938 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates, as indicated, to a fuel injection system, buthas reference more particularly to a system of this character which isespecially adapted for internal combustion engines and the like.

An object of the invention is to provide a fuel injection system, theuse of which will materially reduce the fuel costs in the operation ofan internal combustion engine and dispense with the need for heavy,expensive accessories usually required when utilizing fuel oil for theoperation of such engines.

Another object of the invention is to provide a fuel injection systemwhich is readily adapted for use in connection with existing types ofgasoline engines by virtue of the low first cost of installation of thesystem and the use of a minimum number of new parts for modification ofthe engine proper.

2 To the accomplishment of the foregoing and related ends, saidinvention, then, consists of the means hereinafter fully described andparticularly pointed out in the claim.

The annexed drawing and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting, however, but one of various mechanical forms in which theprinciple of the invention may be used.

In said annexed drawing:

Fig. 1 is a fragmentary transverse cross-sectional view of an internalcombustion engine of the type employed for the propulsion of motorvehicles, and showing a preferred form of the fuel injection system inassociation therewith;

Fig. 2 is a view partly in plan and partly in horizontal cross-sectionof the manifold of the fuel injection system; and

Fig. 3 is a fragmentary transverse cross-sectional view of a manifold,showing the filter or screen in an inclined position.

Referring more especially to Figs. 1 and 2, there is disclosed aninternal combustion engine I, provided with the usual cylinders 2,pistons 3, spark plugs 4 and valves 5.

Secured to the engine is a manifold 6, having outlets I in communicationwith the intake passage 8 of each cylinder. Each of the outlets I isprovided with a throttle valve 9 for controlling the fuel feed to eachcylinder.

Extending vertically upwardly through the bottom or lower wall ID of themanifold and into the interior of the manifold is a series of spray jetsII. These jets extend from a conduit I2 which receives fuel from thefuel tank I3 through the intermediary of conduit I4, pump I5 and conduitI 6. The pump I5 is suitably mounted on the engine and is preferably ofthe rotary, gear or plunger type, capable of discharging fuel atapproximately three hundred pounds pressure. It is driven from theaccessory shaft. The pump draws fuel from the fuel supply tank andforces it through the spray jets II into the intake manifold.

Extending into the manifold 6 at any desired point are air inlets I! forsupplying air to form a fuel-air mixture of the desired properties.

It will be understood that although the spray jets I I serve to deliverthe fuel in a vaporized or atomized condition, some globules orparticles of an unvaporized or unatomized character may be suppliedwhich are too large for proper combustion. For the purpose of preventingsuch globules or particles from entering the intake passages 8 of thecylinders, there is provided a screen I8 preferably extendinghorizontally entirely across the interior of the manifold at a pointsomewhat above the spray jets and dividing the manifold in effect intotwo compartments, one of which designated I9 may be termed a spraychamber and the other of which designated 20, may be termed the airmixing chamber.

Particles which pass through the screen, but are too heavy to becarried. into the cylinder intake passages may fall on the screen anddrop through the screen into the spray chamber.

To facilitate drainage of particles of the aforesaid character, theupper surface 2I of the lower wall IU of the manifold is slopedrearwardly, and a sump or drain outlet 22 is provided which is incommunication with a conduit 23, whereby the particles are returned tothe supply tank I3. To further facilitate drainage, the screen I8 may beinclined, as shown in Fig. 3.

Where the present system is employed in connection with jump sparkignition, as in an internal combustion engine of the characterdescribed, compression pressures as low as to 200 pounds per square inchmay be used, thereby avoiding the necessity of using heavy connectingrods, crankcase, cylinders and bearings, which are required in otheroil-burning engines of high compression type, due to the inherent highstresses on these parts.

The present fuel injection system is readily adapted to be used inconnection with either two or fourcycle engines. Moreover, the use ofthis system dispenses with the the need for cams of special shape, timedfuel pumps and injection valves, as required in other systems.

Various changes may be made without departing from the scope of theinvention. It may, for example, be desirable to place the air inletports in such manner that the air for mixing with the fuel enters thespray chamber l9. Furthermore, provision may be made for adjusting theelevation of the screen l8, or the screen may in fact be placed in anauxiliary or sub-manifold.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by the following claim orthe equivalent of such stated means be employed.

emitting fuel in a finely divided condition.

JOHN S. WALTERS.

